Among the products of the electrocatalytic reduction of carbon dioxide (CO2RR), CO is currently the most valuable product for industrial applications. However, poor stability is a significant obstacle to CO2RR. Therefore, we synthesized a series of bimetallic organic framework materials containing different ratios of tungsten to copper using a hydrothermal method and used them as precursors. The precursors were then subjected to pyrolysis at 800 °C under argon gas, and the M-N bimetallic sites were formed after 2 h. Loose porous structures favorable for electrocatalytic reactions were finally obtained. The material could operate at lower reduction potentials than existing catalysts and obtained higher Faraday efficiencies than comparable catalysts. Of these, the current density of WCu-C/N (W:Cu = 3:1) could be stabilized at 7.9 mA ‧ cm-2 and the FE of CO reached 94 % at a hydrogen electrode potential of -0.6 V (V vs. RHE). The novel materials made with a two-step process helped to improve the stability and selectivity of the electrocatalytic reduction of CO2 to CO, which will help to promote the commercial application of this technology.

Abstract
1. Introduction
2. Experimental Procedure
    2.1. Chemicals
    2.2. Synthesis of WCu-C/N composite
    2.3. Electrochemical measurement
3. Results and Discussion
    3.1. Characterization
    3.2. Electrochemical performance
    3.3. Reaction mechanism of WCu-C/N for CO2 reductionto CO
4. Conclusion
References
Author Information

• Kai Chen(School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou 215009, China, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China)
• Zeda Meng(School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou 215009, China)
• Yao Liu(School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou 215009, China)
• Yilei Sun(School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou 215009, China)
• Yuan Liang(School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China) Corresponding author
• Won-Chun Oh(Department of Advanced Materials Science & Engineering, Hanseo University, Seosan 31962, Republic of Korea) Corresponding author